Many manufacturing or converting processes that employ a web of material can perform better with some form of tension control. Tension control is not limited to web processes. Early forms of tension control can involve a friction device such as a leather belt drape over a unwind roll of web material. Adding weight to the end of the leather belt could increase unwind tension and removing weight could lighten web tension. As technology improvements were applied to web processes, brakes, clutches or other torque devices could be coupled to unwind and rewind shafts to apply tension torque to the web material. For certain processes, such open loop tension control is inexpensive and can provide the necessary control to produce acceptable products. In processes that require tighter tension control, solutions often include applying additional sensors to the application and sometimes closing the tension loop with a tension transducer. However, the installation of sensors such as diameter sensors or tension sensors can involve significant expense or can prove impractical because of substantial re-configuring of the web processing equipment to accommodate such sensors.